Apparatus for making plastic articles



April 17, 1962 E. l. VALY] APPARATUS FOR MAKING PLASTIC ARTICLES 13Sheets-Sheet 1 Filed Nov. 3, 1959 11! .lllA

1 INVENTOR E. l. VALYI 3,029,468

13 Sheets-Sheet 2 April 17, 1962 APPARATUS FOR MAKING PLASTIC ARTICLESFiled Nov. 3, 1959 E. l. VALYI APPARATUS FOR MAKING PLASTIC ARTICLESApril 17, 1962 13 Sheets-Sheet 5 Filed Nov. 5, 1959 INVENTOR fmsey zV44Y/ April 17, 1962 E; VALYl 3,029,468

APPARATUS FOR MAKING PLASTIC ARTICLES Filed Nov. 3, 1959 15 Sheets-Sheet4 April 17, 1962 E. 1. VALYl 3,0

APPARATUS FOR MAKING PLASTIC ARTICLES Filed NOV. 3, 1959 15 Sheets-Sheet5 INVENTOR ENE/FY f. M44 Y/ W NEY 13 Sheets-Sheet 6 Iii: Ill! INVENTOREwaev V44 Y/ E. l. VALYI APPARATUS FOR MAKING PLASTIC ARTICLES x m a W 45 1/ Q 2 v/ //v/ V w y & m a

A ril 17,1962

Filed Nov. 3, 1959 ATTORNEY A ril 17, 1962 E. l. VALYI 3,029,468

APPARATUS FOR MAKING PLASTIC ARTICLES Filed Nov. 5, 1959 15 Sheets-Sheet7 INVENTOR E/VfRYj. l/AL Y/ April 17, 1962 E. l. VALYl APPARATUS FORMAKING PLASTIC ARTICLES 13 Sheets-Sheet 8' Filed Nov. 3, 1959 ESQ.ENERYJI VAL Y/ A'ITORNEY April 17, 1962 E. VALYl APPARATUS FOR MAKINGPLASTIC ARTICLES Filed Nov. 5, 1959 15 Sheets-Sheet 9 29 I? 6 v A\.,,},''&$: 7/

, I III I /8. l9 i 20a VENTOR ATTORNEY April 17, 1962 E. 1. VALYI3,029,468 APPARATUS FOR MAKING PLASTIC ARTICLES Filed Nov. 5, 1959 1 3Sheets-She t.10

Ill/II ll/Ill ENTOR EMEEY .l/A4Y/ April 17, 1962 E. l. VALYl 3,029,468

I APPARATUS FOR MAKINGPLASTIC ARTICLES Filed Nov. 5, 1959 15Sheets-Sheet 11 23/ mvswrok E/VE'RY Z VALY/ April 1962 E. 1. VALYI3,029,468

APPARATUS FOR MAKING PLASTIC ARTICLES Filed Nov. 5, 1959 15 Sheets-Sheet12 Q SEC 1 i @44 Zz INVENTOR EMERY I. VALY/ ATTORNEY April 17, 1962 E.l. vAgYl 3,029,468

APPARATUS FOR MAKING PLASTIC ARTICLES Filed Nov. 3, 1959 13 Sheets-Sheet13 mVENTOR EMERY 1'. (/AL Y/ ATTORNEY United States Patent I 3,029,468APPARATUS FOR MAKING PLASTIC ARTICLES Emery I. Valyi, New York, N.Y.

(% ARD Corporation, 20 S. Broadway, Yonkers 1, N.Y.) Filed Nov. 3, 1959,Ser. No. 850,696 26 Claims. (01. 18-5) This invention relates toapparatus for molding of hollow objects made of organic plasticmaterials. More particularly, it relates to apparatus for manufacture ofbottles by producing a pre-form and subsequently expanding it to thedesired hollow form under the action of internal pressure.

Hollow articles such as bottles have been produced by the method knownas blow molding. In that method, a tubular pre-fo-rm, herein referred toas a parison, is produced by extrusion, pressing, or injection molding.The parison is then placed within a die whose interior corresponds tothe shape of the hollow article to be made, clamped firmly therein, andexpanded through application of internal fluid pressure, untilconformance to the shape of the die is obtained. When an extruded tubeis used for this purpose, both ends must be closed, such as bypinching-off, i.e. pressure welding, before fluid pressure is admittedfor the purpose of expansion. When an injection molded or pressedparison is used, it has been customary to transfer it from the injectionmolding or pressing tool into the blow mold. The former procedure hasthe disadvantage of necessitating a weld seam to be formed where thetubing is pinched off, the latter of requiring the transfer of theparison from one tool to another.

Transfer of the parison renders the respective process slow, spaceconsuming and difficult to control. Attempts were made to combine thetwo tools, namely the one in which the parison is formed and the one inwhich the parison is expanded into its final form under internal fluidpressure, by placing the former tool retractably within the latter,thereby avoiding the need for moving the parison. The use of suchcombined tools was not advantageous heretofore because they gave rise toprolonged operating cycles due to the need to allow the parison to coolbefore the retractable portion of the combined tool could be movedwithout damage to the parison. A further disadvantage of such combinedparison and blow tools was the ditliculty in placing the gate and runnersystem in a manner obviating removal of the gate for best appearance andperformance of the bottle. Because of that difficulty, an additionalmanufacturing step was often required subsequent to the removal of thearticle from the blow mold, such as to sever the gate and runner residuefrom the article.

Extraction of the product from the mold in which it reached its finalshape, the blow mold, was diflicult, usually requiring continuedapplioation of internal pressure to aid such extraction.

An object of this invention is to provide a new and improved moldingmechanism for making hollow articles, such as bottles, flasks, cups, andthe like.

Another object of this invention is to provide an improved mechanismcapable of producing a parison and the article formed from it by theapplicationof internal fluid pressure, without moving the parison inrelation to the blow die except to the extent that the parison isexpanded.

An additional object of this invention is to provide an improvedapparatus for producing a finished hollow article without at the sametime producing a gate or runner residue to be removed from the hollowarticle after its extraction from the blow mold, or to be removedseparately from the die structure used to produce the parison.

A further object of this invention is to provide convenient andeconomical means for the extraction of the finished hollow article fromthe blow mold.

A still further object of this invention is to provide improved means toproduce a parison and to expose it with-in the blow mold for expansionunder the influence of internal fluid pressure, without subjecting theparison to stresses capable of damaging it.

A still further object of this invention is to provide improved means toproduce a parison permitting predetermined desirable wall thicknessdistribution of the finished article.

Other and additional objects will become apparent hereafter.

The objects of the invention are accomplished in general by providing amolding machine having two platens movable in relation one to the other,one of which carries a die member designated as the cover die and theother a die member designated as the body die. The cover die contains achannel, connecting a supply of heated molding material with the cavityintended to contain the parison. The body die includes a :rctnactablemember designated as the shoulder slide and parallel there with a memberdesignated as the blow-tube, as well as a retractable member designatedas the bottom slide. The shoulder slide is constructed so as tocooperate with the body die, when in a retracted position, to form asubstantial portion of the bottle shoulder and, usually, the bottle neckwhich may carry a thread on its outside if required. The movement of theshoulder slide takes place in a direction parallel to and usually, butnot necessarily, concentric with the blow-tube and when positionedwithin the body die assembly rather than retracted as above, thatportion which forms part of the bottle shoulder and the bottle neck ispositioned entirely below the end of the blow-tube and usually outsideof the blow die cavity. When so positioned, the shoulder slide andblow-tube combine to form a cylindrical die cavity which may be closedby forcing the body die against the cover die, thereby com pleting theparison die cavity. It will be noted that the portion of the shoulderslide later to form the bottle neck and shoulder is now in juxapositionwith or below that end of the parison which later on is to form thebottom of the hollow article. After injecting the parison through thecover die, it is possible to retract the shoulder slide over the parisonwithout dimensional interference. After retracting the shoulder slideand closing the body die cavity by positioning the bottom slideappropriately, fluid pressure is admitted to the inside of the parisonthrough the blow-tube, causing the parison to expand to the walls of thebody die, it being noted that the tip of the shoulder slide previouslypositioned at the bottom of the parison is now in juxtaposition withthat portion of the parison which is to form the neck and at least partof the shoulder of the finished bottle. Thus the finished hollow articleis produced Within a die cavity defined by the bottom closure, or bottomslide, by the body die, and, at its shoulder and neck, by the shoulderslide.

It is obvious to those skilled in the art of producing hollow articles,and particularly bottles, that most materials from which the parison andlater ,on the bottle is made are capable of softening upon exposure toheat and hardening again when cooled; and 'it is also obvious that theinjection of the parison takes place while the material is heated to atemperature appropriate for rendering the material injectable, thatexpansion due to internal fluid pressure takes place while the materialis still warm enough to be deformable and that the hollow articleremains under internal fluid pressure in the blow die subsequent to itsexpansion until it has cooled sufliciently to become rigid and capableof handling without deleterious deformation.

While the shoulder slide is retracted toward the position which it willassume while the blowing step takes place, and after the bottom slide ispositioned to close the blow die, vacuum may be applied within the blowdie cavity to enhance the pressure differential between the inside andoutside of the parison, thereby facilitating the blowing step. Vacuummay be further applied so as to minimize the amount of air remainingbetween the outside surface of the blown article and the inside surfaceof the blow mold cavity, since air tends to form an insulating layerreducing the eifectiveness of cooling within the blow mold, therebylengthening the time that must elapse before the finished article may beremoved from the blow mold. Further to enhance the effectiveness ofcooling, the blow mold cavity may also be flushed with a gas of betterheat conductivity than that of air.

After the material of the hollow article has become comparatively rigidand strong by cooling within the blow die, it is removed therefrom. Forexample, the bottom slide is withdrawn and the shoulder slide advancedin the direction of that position which was mentioned at the outset asdefining the parison cavity. In the course of such movement, theshoulder slide will push the. bottle out of the body die cavity, usuallygripping the bottle firmly at the neck, and bearing against asubstantial area of the shoulder. The bottle may thus be removed fromthe cavity without undue deformation, to a position outside the bodycavity which is accurately defined and therefore suitable forpositioning in devices capable of transferring the bottle to subsequentoperations such as decorating or packaging. In order to release thebottle from the hold of the shoulder slide, that portion of the shoulderslide which is in contact with the bottle neck may be parted, forexample through the use of a segmented ring. The bottle may also beunscrewed, or pushed off by differential action of concentric portionsof the blow-tube, or it may be blown oli under internal fluid pressure.

The finished article may also be ejected from the blow mold in variousother ways as hereinafter described.

The nature of the invention and the various embodiments thereof will bebetter understood by reference to the following description taken inconnection with the accompanying drawings, wherein:

FIG. 1 is a central section of one form of bottle which is adapted to beproduced by the molding mechanism as shown in FIGS. 2 to 8;

FIG. 2 is a central section through the parison from which the bottomshown in FIG. 1 is produced;

FIG. 3 is a central vertical section through one form of moldingapparatus of the invention showing the dies, slides and blow-tube shapedto produce the bottle shown in FIG. 1, and with the various elements,thereof in position for the blow-tube to be withdrawn subsequent to theejection of a finished bottle from the mechanism by one type of meansprovided;

FIG. 3A is a fragmentary detail view in elevation showing the bottomslide mechanism in closed position as viewed from the line 3A-3-A onFIG. 3;

FIG. 4 is a transverse vertical section on the line 4-4 on FIG. 3;

FIG. 5 is an enlarged detail horizontal section showing the variousparts of the mechanism in position for the molding material to beinjected into the mechanism to form the parison, and with the parisonformed therein;

FIG. 6 is a view similar to FIG. 5 showing the body die, the shoulderslide and blow-tube withdrawn from the cover die, the shoulder slideretracted in the body die to bottle forming position, the bottom slidemeans closing the open end of the body die, and the parison expandedfrom its initial position into bottle forming position in contact withthe body die, the shoulder slide and the bottom slide means;

FIG. 7 is a view similar to FIGS. 5 and 6 showing the bottom slide meansin open position, and the shoulder slide, and the finished bottlecarried thereby, projected i out from the body die through the openbottom slide means in position for the finished bottle to be strippedfrom the shoulder slide;

FIG. 8 is a view similar to FIG. 6 showing a slightly modifiedconstruction of body die and shoulder slide;

FIG. 9 is a detail section taken on the line 9-9 on FIG. 8;

FIG. 10 is an enlarged fragmentary detail section showing one way ofejecting the bottle of FIG. 1 from the mechanism shown in FIG. 3;

FIG. 11 is a view similar to FIG. 10 showing another way in which thebottle of FIG. 1 may be ejected from the mechanism showin in FIG. 3;

FIG. 11A is a transverse detail section taken on the line 1lA-11A onFIG. 11;

FIG. 12 is a view sirnilar to FIG. 6 showing the bottom slide means inopen position, and the shoulder slide and the finished bottle carriedthereby projected out from the body die through the open bottom slidemeans;

FIG. 13 is a detail sectional view showing the blowtube of FIGS. 3 to 5modified in a manner to provide the neck of the bottle shown in FIG. 1with interior threads;

FIG. 14 is a detail sectional view showing a modified type of blow'tubewhich may be used in place of the blow-tube shown in FIGS. 3 to 8;

FIG. 15 is a view similar to FIG. 3 showing a modified type of mechanismfor producing the bottle shown in FIG. 1 and for ejecting it therefrom;

FIG. 16 is an enlarged detail section taken on the line 16-16 on FIG.15;

FIG. 17 is a central horizontal section showing a modified type ofmechanism in which the body die and shoulder slide are each made up oftwo similar halves which are transversely movable into and out ofengagement with each other, and in which the shoulder slide islongitudinally movable in either open or closed position;

FIG. 18 is a fragmentary detail sectional view showing the body die andthe shoulder slide of FIG. 17 closed with the shoulder slide in bottleforming position;

FIG. 19 is a transverse section taken on the line 19-19 on FIG. 18;

FIG. 20 is a fragmentary detail sectional view showing a modified typeof body die in which the mid-section thereof is made in two similarhalves which are slidably mounted in the body die and are movable intoand out of engagement with each other, the body die, shoulder slide andblow-tube being in parison forming position which necessitates the twohalves of the mid-section being in separated or open position;

FIG. 21 is a view similar to FIG. 20 showing the body die, shoulderslide and blow-tube in bottle forming position with the two halves ofthe mid-section in closed position;

FIG. 22 is a transverse fragmentary section taken on the line 2222 onFIG. 21;

FIG. 23 is a view partially in elevation and partially in sectionshowing the bottle which is molded by the mechanism shown in FIGS. 20 to22;

FIG. 24 is an enlarged fragmentary detail section showing a modifiedtype of bottom slide means enabling the indenting of the bottom of abottle as it is molded;

FIG. 25 is a view, partially in elevation and partially in section, of abottle produced by the mechanism shown in FIG. 24;

FIG. 26 is a fragmentary detail sectional view showing a modified typeof shoulder slide and blow-tube in parison forming position;

FIG. 27 is a view similar to FIG. 26 showing the shoulder slide andblow-tube of FIG. 26 in bottle forming position;

FIG. 28 is an enlarged fragmentary sectional view showing still anothermodified type of shoulder slide and blow-tube in parison formingposition;

FIG. 29 is a view, partially in section and partially in elevation, ofanother form of bottle capable of being produced by the mechanism;

FIG. 30 is a fragmentary detail sectional view showing the modified typeof shoulder slide used in producing the bottle shown in FIG. 29 inparison forming posltion;

FIG. 31 is a view similar to FIG. 30 showing the shoulder slide of FIG.30 in bottle forming position;

FIG. 32 is a view, partially in elevation and partially in section, ofanother type of bottle capable of being produced in accordance with thepresent invention;

FIG. 33 is a fragmentary detail sectional view showing the modified typeof body die, shoulder slide and blow-tube, used in producing the bottleshown in FIG. 32, in parison forming position;

FIG. 34 is a View similar to FIG. 33 showing the body die, shoulderslide and blow-tube of FIG. 33 in bottle forming position;

FIG. 35 is a view, partially in elevation and partially in section ofstill another type of bottle capable of being produced in accordancewith the present invention;

FIG. 36 is a fragmentary detail sectional view showing the modified typeof shoulder slide and blow-tube, used in producing the bottle shown inFIG. 35, in parison forming position;

'FIG. 37 is a view similar to FIG. 36 showing the shoulder slide andblow-tube of FIG. 36 in bottle forming position;

FIG. 38 is a view, partially in section and partially in elevation, of acup capable of being produced in accordance with the present invention;

FIG. 39 is an enlarged fragmentary sectional view showing a modifiedtype of body mold, shoulder slide and blow-tube, used in producing thecup shown in FIG. 38, in parison forming position;

FIG. 40 is a view similar to FIG. 39 showing the body die, shoulderslide and blow-tube of FIG. 39 in cup forming position;

FIG. 41 is an enlarged detail sectional view showing a modified form ofshoulder slide and blow-tube of FIGS. 39 and 40;

FIG. 42 is a sectional view of a pair of bottles, capable of beingproduced in accordance with the present invention, in which the bottomsthereof are indented in such a manner that the bottles can be nested oneabove the other; i

FIG. 43 is a view similar to FIGS. 3, and 17 showing the cover die, thebody die, the shoulder die and the blow-tube, used in producing thebottle shown in FIG. 42, in parison forming position;

FIG. 44 is a view similar to FIG. 43 showing the cover die, the bodydie, the shoulder slide and the blow-tube of FIG. 43 in bottle formingposition;

FIG. 45 is a View similar to FIGS. 43 and 44 showing the finished bottlewithdrawn from the body die into position to be ejected from themechanism; and

FIG. 46 is a transverse section taken on the line 46-46 on FIG. 46.

The various forms of the invention disclosed herein, and the mode ofoperation thereof, will now be specifically described in connection withthe drawings by the use of reference numbers, it being understood thatlike numbers indicate similar parts throughout the drawings.

FIG. 1 shows one type of bottle, generally indicated by the numeral 1,capable of being produced according to the invention; and FIG. 2 showsthe parison, generally indicated by the numeral 2, from which the bottleis expanded under fluid pressure. the bottles are formed of organicplastic materials such as for example, polyethylene, polystyrene, orpolyvinyl chloride.

The bottle comprises the cylindrical body section 3, the bottom 4, theshoulder 5, and the neck 6 which is exteriorly threaded as indicated at7; and the parison 2 consists of an elongated cylindrical tube 8 whichis closed As previously stated,

6 at one end thereof as indicated at 9, and is open at the other endthereof as shown at 10.

Reference will be had first to FIGS. 3 to 7 of the drawings, which showa mechanism constructed for producing the bottle 1, and for purposes ofclarity of description the right-hand side of the mechanism, as shown inFIG. 3, will be referred to as the front or forward end of themechanism, and the lefthand side thereof as shown in FIG. 3, will bereferred to as the rear or rearward end of the mechanism.

As shown in FIGS. 3 to 7, the mechanism of the invention comprises apair of spaced parallel vertically disposed supporting plates 11 and 12which are rigidly secured in fixed position upon a base or floor 13, theplates 11 and 12 are connected together by four cylindrical rods 14which are secured to and between the plates 11 and 12. A frame,generally indicated by the numeral 15, which comprises a forward platen16 and a rear platen 17 connected together by a plurality oflongitudinally extending connecting members 18' integral there with, isslidably mounted upon the rods 14 for longitudinal back and forthmovement thereon. The front face of the forward platen 16 is providedwith a plurality of spaced parallel vertically extending T slots 19 uponwhich a body die 20 is removably secured to the front face of the platen16 by bolts 21 and lugs 22. The body die 20 is provided with cylindricalcavity 23 therethrough, the rear end of which is disposed in registerwith a complementary bore 24 in the platen 16.

A cylindrical shoulder slide 25 having an axial bore 26 is reciprocallymounted in the aligned bores 23 and 24 of the body die 20 and the platenrespectively. The forward end of the shoulder slide 25 is provided witha concave surface 27 which is complementary to the convex shouldersection 5 of the bottle 1. The forward end of the bore 26 in theshoulder slide 25 is provided with internal threads 28 which arecomplementary to the external threads 7 on the neck of the bottle 1.

A blow-tube, generally indicated by the numeral 29, is reciprocally androtatably mounted in the bore 26 in the shoulder slide 25. The blow-tube29 comprises an elongated cylindrical body section 30, of the samediameter as the bore 26, in which it is mounted, and a reduced elongatedcylindrical extension 31 which extends forwardly from the body section30' in axial alignment therewith, thereby providing an annular shoulder32 between the body section 39 and the extension 31.

A cover die, generally indicated by the numeral 33,

is secured to the rear face of the supporting plate 11 in axialalignment with the blow-tube 29, shoulder slide 25 and the body die 20.The cover die 33 comprises a base 34, by which it is secured to theplate 11, and rearwardly extending cylindrical section 35, the rear endof which has a surface 36 in part complementary to the concave forwardend 27 of the shoulder slide 25. A short cylindrical extension 37fitting into the bore 26 in-the shoulder slide 25 extends rearwardlyfrom the rear surface 36 of the cover die section 35. The cover die 33is provided with an axial conduit 38 which is connected through a nozzle39 to a source of molding material, not shown.

The body die 20 is provided with a shoulder 40 at the forward endthereof, the front face of which is flush with the front face of thebody die. A pair of opposed similar slides 41 and 42 by which theforward end of the body die cavity 23 is adapted to be opened and closedare slidably mounted upon the front face of the body die between gibbs43 for movement toward and away from each other. The slide 41 is adaptedto be actuated by a fluid operated piston 44 which is connected to theslide 41 by a piston rod 45 and is reciprocally mounted in a cylinder 46secured to the shoulder 40 as indicated at 47; and the slide 42 isadapted to be actuated by a fluid operated piston 48 which is connectedto the slide 42 by a piston rod 49 and is reciprocally mounted in acylinder 50 secured to the shoulder 40 as indicated at 51.

The slides 41 and 42 are provided with similar semicircular recesses 41and 42 respectively which, when the slides 41 and 42 are in closedposition, are adapted to register with each other and form a shallowcircular recess in axial alignment with the body die cavity 23.

A forwardly extending elongated cylinder 55 having an axial bore 56therein is attached integrally to the rear platen 17. An elongatedforwardly extending cylindrical sleeve 57, the inside diameter of whichis greater than the outside diameter of the cylinder 55, is alsosuitably secured to the rear platen 17 co-axially with the cylinder 55,thereby providing an annular chamber 53 between the cylinder 55 andsleeve 57. A tubular piston 59 is reciprocally mounted on the cylinder55 with the enlarged rear end 60 thereof disposed within the annularchamber 58 and the outwardly extending end 61 thereof secured to therear side of a plate 62. The rear end of the shoulder slide 25 isconnected to the front face of the plate 62 by connecting links 63 whichstraddle a plat 64 interposed between the plate 62 and the rear end ofthe shoulder slide 23. A piston 65 which is reciprocally mounted in thebore 56 of the cylinder 55 is connected to the rear side of plate 64 bya connecting rod 66 which extends through an aperture 67 in the plate62. The rear end of the blow-tube 29 which extends out from the axialbore 26 in the shoulder slide 25 is connected to the front face of theplate 64. A cylinder 68 which is suitably secured to the rear support 12and extends rearwardly therefrom has a piston, not shown, reciprocallymounted therein which is connected to the rear platen 17 of the carriageby a piston rod 69.

From the foregoing it will be apparent that the carriage 15, and all ofthe mechanism carried thereby, can be moved back and forth toward andaway from the cover die 33 by the piston mounted in the cylinder 68;that the shoulder slide 25 is adapted to be advanced and retracted inthe cavity 23 in the body die 20, by the tubular piston 59, and that theblow-tube 29 is adapted to be advanced and retracted in the axial bore26 in the shoulder slide 25 by the piston 65. Operating fluid is adaptedto be supplied to and exhausted from the various cylinders 44, 45, 56,58 and 68 through various conduit means, all generally indicated by thenumeral 70. The supply of fluid to the various cylinders is controlledby suitable valve means, not shown, which may be automatically operatedto supply fluid to the various cylinders in sequentially timed relationso that the operaiton of the mechanism may be fully automatic.

The blow-tube 29 is provided with a fluid passageway 71 which extendssubstantially the full length of the blow-tube and is connected at therear end thereof to a fluid passageway 72 in the plate 64, and at theforward end thereof to a plurality of outlet passageways 73 which aredisposed in and extend out to the periphery of the reduced forwardextension 31 of the blow-tube 29. Fluid under pressure is supplied tothe passageways 71 to 73 through a flexible conduit 74 which isconnected to the passageway 72 in the plate 64.

The body die and shoulder slide are each provided with a plurality oflongitudinally extending connecting passageways 75 through which acooling or heating medium may be circulated during operation to maintainthe body die and shoulder slide at an optimum temperature, for molding,first the parison 2 and then the bottle 1. The body die 20 is providedwith an outlet passageway 76 through which air may be exhausted and/ordischarged during the expanding of the parison into bottle shape.

The operation of the'mechanism thus far described will now be explained.As previously stated the parison 2 is formed within the shoulder slide25 while the latter is placed within the confines of the body die 2%,and then expanded by fluid pressure into bottle shape in accordance withthe configuration of the cavity 23 of the body die, the forward end 27of the shoulder slide 25 and the recesses 41, 42 in the inner face ofthe bottom slides 41 and 42. With the bottom slides 41 and 42 in openposition, as shown in FIGS. 3 and 5, the shoulder slide 25 and theblow-tube 29 within the bore 26 of the shoulder slide 25 are brought tothe position shown in FIG. 5. The frame 15 and all of the mechanismcarried thereby is then moved forwardly until the forward end 27 of theshoulder slide 25 is in firm contact with the rear end 36 of the coverdie 33, and the extension 37 disposed within the bore 26 of the shoulderslide 25, with the rear surface of the extension 37 spaced a shortdistance from the forward end of the reduced extension 31 of theblow-tube 29, all as shown in FIG. 5. Cover die extension 37 is soconstructed as to prevent the flow of plastic forwardly from its rearsurface. For that purpose a sealing land or taper, not shown, may beprovided upon extension 37, with a corresponding land or taper upon thejuxtaposed portion of the shoulder slide 25. Or if preferred the bodydie 20, with the shoulder slide 25 and the blcw-tube 29 retracted, maybe moved to the position shown in FIG. 5 and then the shoulder slide andblow-tube projected to the positions shown in FIG. 5. After the variouselements have been brought to the positions shown in FIG. 5, heatedflowable molding materials is projected under pressure into the bore 26of the shoulder slide 25 about the reduced forward end 31 of theblow-tube between the shoulder 32 and the end of the extension 37. Thebody die is moved after a brief interval to the position shown in FIG. 3and the shoulder slide 25 is retracted to the position shown in FIG. 6leaving the parison 2 upon the reduced forward end 31 of the blow-tubewithin the cavity 23 of the body die as shown in dotted lines in FIG. 6.While the shoulder slide 25 is being retracted, the parison isconstrained against shoulder 32 of the blow-tube and within the shoulderslide bore. Within its constrained portion the parison is thereforesubjected to compressive forces if friction is developed between theparison and the shoulder slide in the course of relative movement of thetwo. Organic plastic materials are frequently capable of developing suchfrictional forces by virtue of their tackiness at elevated temperature.The prevalence of compressive forces will aid in preserving the parisonintact and thus reduce the hazard of surface tears and fissures. Thebottom slides 141 and 42 are moved to closed position as shown in FIG.6. Fluid under pressure is then applied to the inside of the parison 2through the conduit 71 and through passageway 73 or fluid pervious areasarranged in their place which expands the parison, while still inplastically deformable condition, into body shape in contact with theinner walls of the body die, shoulder slide 25 and bottom slides 41 and42. Briefly preceding or simultaneously with the admission of pressurefluid into conduit 71, air contained within the body die 20 may beexhausted through vacuum conduit 76. Thus a pressure differential isestablished within the inside and outside of the parison, amounting toapproximately 14 pounds per square inch in the event that body die 20 isconnected to vacuum and conduit 71 only to the atmosphere, up to severalhundred pounds per square inch, the pressure differential depending uponthe nature of the material to be molded, the temperature at whichdeformation of the parison is to take place and the rate of heatdissipation of the molding material desired. After the shaped bottle hascooled and hardened to set condition the bottom slides 41 and 42 aremoved to open position and the shoulder slide 25 and with it thefinished bottle, are projected out from the body die into the positionshown in FIG. 7 after which the bottle is removed from the shoulderslide.

FIGS. 8 and 9 show a slightly modified form of body die and shoulderslide which may be used in place of the body die 20 and the shoulderslide 25 shown in FIGS. 3 to 7. As shown therein the shoulder slide 25is of lesser outside diameter than the mold cavity 23 of the body dieand is slidably mounted in an axial bore 87 in a rear wall 88, of thebody die 20, which intersects the cavity 23. The forward face 89 of therear wall 88, about the bo e 87, is of the same curvature as thecurvature 27 of the forward end of the shoulder slide and coactstherewith to form the shoulder of the bottle 1. Otherwise theconstruction and operation is the same as FIGS. 3 to 7.

The fluid passageways 75 in the body die 20 and the shoulder slide 25through which a cooling medium is adapted to be circulated, are providedto enhance the cooling of formed bottles. Although not shown, it isobvious that the bottom slides 41 and 42 may be provided withpassageways similar to the passageways 75 through which a cooling mediummay be circulated. The blow-tube 29 is normally not cooled other than bythe fluid passing through it during the blowing of the parison to bottleshape, so as to keep the inner surface of the parison at a temperaturesuitable for blowing. In in stances where cooling is critical for thesake of optimum operating cycles the forward end of the shoulder slideis preferably constructed from a material of high heat conductivity andhigh heat capacity such as copper, beryllium-copper or copper-chromiumalloys which may be also artificially cooled. An insulating layer 86 inthe form of a refractory gasket between the forward end and theremainder of shoulder slide 25 may be provided, since it is notalwaysdesirable to cool the entire shoulder slide uniformly. Excessive coolingof the bulk of shoulder slide 25 would at times result in unwantedchilling of the parison rendering its subsequent expansion difiicult.During the injecting of the molding material to form the parison, thatportion of the molding material which is to form the neck 6 of thebottle 1 will have moved the greatest distance from the injection nozzle38 in the cover die 33 and will therefore be the coolest when theblowing operation is started. In order to safeguard against undesirablecooling in that area, artificial heating means such as electricresistance heaters, not shown, may be provided. Internal cooling and/ orheating of shoulder slide 25 is not always used. Instead, the shoulderslide may be subdivided into a forward end of high conductivity and theremainder, of indifferent conductivity, at times separated by aninsulating layer 86, whereby the forward end may be cooled externally,such as with an air blast or liquid coolant, only while in the positioncorresponding to FIG. 6.

The blown bottle is subjected to internal pressure while it cools sinceotherwise it would separate from the chillin g walls of body die 20 dueto thermal shrinkage rendering heat transfer into the die ineffective.

The finished bottles may be removed in various different ways, dependingupon the configuration of the bottle and the type of molding materialfrom which it is made. With some types of molding material, the bottleis sufliciently pliable and deformable that the bottle may be strippedfrom the shoulder slide, such as through action of shoulder 32 ofblow-tube 29, Without injury to the neck threads of the bottle as theyare stripped from the thread forming grooves 28 about the forward end ofthe shoulder slide bore 26.

Another way of removing the bottle is to unscrew it from the shoulderslide as shown in FIGS. 3 and 10. As shown therein the body section 30of the blow-tube 29, which is rotatably mounted in the shoulder slidebore 26 is made in the form of an elongated pinion 80 which is inconstant mesh with a transversely extending rack 81 which is adapted tobe reciprocated by a piston 82 in a cylinder 83 mounted upon the forwardplaten 16. The shoulder 32 of the blow-tube 29 is provided with aforwardly extending lug 84 (FIG. 10) which becomes embedded in thebottle neck during the forming of the parison. The blow-tube is thenrotated by the rack and pinion 81, 80 in the proper direction to unscrewthe threaded neck of the bottle from the thread forming groove 28 of theshoulder slide, While at the same time the blow tube is being advancedat the same rate that the bottle is b- 7 ing unscrewed. FIGS. 11 and 12show a'slightly modified means for unscrewing the bottle from theshoulder slide. As shown therein an elongated key is substituted for thelug 84 of FIG. 10 which obviates the necessity of advancing theblow-tube during the unscrewing of the bottle, or of limiting theunscrewing operation to the position of the blow-tube shown in FIG. 3.Otherwise the construction and operation are the same as in FIGS. 3 and10. Various other means are disclosed herein for removing the finishedbottle from the mechanism which will be described hereinafter.

FIGS. 15 and 16 show a modified form of the mechanism disclosed in FIGS.3 to 7. In referring to FIGS. 15 and 16 the left hand side of FIG. 15will be considered the forward end of the mechanism, and the right handside will be considered the rear end of the mechanism; and like parts inFIGS. 15 and 16, and FIGS. 3 to 7 will be given like numerals. As shownin FIG. 15 the body die 20 has a plurality of cars integral therewith,by which it is slidably mounted upon the rods 14; and the shoulder slide25 is removably secured by bolt and T-slot connections 91, to a rearplaten 92 having cars 93 by which it is slidably mounted upon the rods14. The body die 20 is adapted to be moved back and forth toward andaway from the cover die 33 by pistons 94 which are mounted in cylinders95, carried by the front support 11, and connected to the ears 90 bypiston rods 96. In the form shown in FIG. 15, the cylinder 57 and thetubular piston 59 of FIG. 3 are omitted, and the cylinder 55, in whichthe actuating. piston 65 for the blow-tube 29 is mounted, is secured tothe forward end of the piston rod 69 which extends forwardly out of thecylinder 68 secured to the rear face of the rear support 12. The forwardend of the cylinder 55 is connected to the rear face of the platen 92 bythe links 63. From this it will be seen that by actuating the piston rod69 by the piston connected thereto within the cylinder 68, the shoulderslide 25, and the blow-tube 29 mounted therein, may be projected intothe body die 20 and out through the forward end thereof into engagementwith the cover die 33, with the bottom slides 41 and 42 in openposition, then retracted back into the body die 20 for the expanding ofthe parison into bottle shape, and then withdrawn back out of the bodydie to the position shown in FIG. 15 for the removal of the bottle. Inthis form of the mechanism the shoulder slide 25- is provided with adifferent neck forming means which greatly facilitates the removal ofthe bottle from the shoulder slide. As shown in FIGS. 15 and 16, theshoulder slide 25 carries just rearwardly of the front concave face 27thereof a transverse rectangular slot which extends through the shoulderslide. In the slot 100 are slidably mounted a pair of similar opposedslides 101 and 102 Which are adapted to be positively forced together asthe shoulder slide 25 is projected into the body die 20 and to be springpressed apart when the shoulder slide is withdrawn back out of the bodydie. The outer ends of the slides 101 and 102 have the same curvature asthe outer periphery of the shoulder slide and the length of the slides101 21161102 is such that the outer ends thereof are flush with theouter periphery of the shoulder slide when the inner ends thereof are incontact with each other. The forward edges of the outer ends of theslides 101 and 102 are bevelled as shown at 103 and 104, whereby the twoslides are forced inwardly into engagement with each other as theshoulder slide is projected into the body die. The inner ends of theslides are provided with opposed similar complementary semi-circularinteniorly threaded sections 105 and 106 which, when the inner ends ofthe slides 101 and 102 are in engagement with each other when theshoulder slide is within the body die, form the threaded neck of thebottle.

When-the shoulder slide, and with it a molded bottle, are withdrawn fromthe body die 20 to the position shown in FIG. 15, the slides 101 and 102are forced apart by springs 16! which are disposed about bolts 103 bywhich the outward movement of the slides 101 and 102 is limited. Theseparation of the slides 101 and 102 releases the neck of the bottle, asshown in FIG. 16, thereby permitting ready removal of the bottle fromthe mechanism. Otherwise the construction and mode of operation of themechanism shown in FIGS. 15 and 16 is the same as that shown in FIGS. 3to 6.

FIG. 23 shows a bottle, generally indicated by the numeral 115, which issimilar to the bottle shown in FIG. 1 with the exception that the sidewall 3 intermediate the bottom 4- and shoulder 5 is constricted as shownat 116. The production of this type of bottle requires a modified formof body die 20 in order to permit the projection of the shoulder slide25 out through the forward end of the body die into engagement with thecover die 33 in parison forming position, and to permit the ejection ofthe formed bottle out of the body die. Such a body die 20 is shown inFIGS. 20 to 22 inclusive. As shown therein the body die 20 is providedwith an elongated rectangular recess 117 which intersects the cavity 23thereof. A pair of similar opposed slides 118 and 119, are slidablymounted in the recess 117 adapted to be moved into and out of engagementwith each other by suitable means, such as for example by cylinders andpistons, not shown, through piston rods 120 and 121. The opposed innerends of the slides 118 and 119 are each provided with a semi-circularrecess 122, having the same contour as the constricted section 116 ofthe bottle 115. When the slides 118 and 119 are in closed engagingposition, as shown in FIGS. 21 and 22, the recesses 122 co-act with eachother to form the constricted section 116 of the bottle 115; and whenthe slides 118 and 119 are in separated position as shown in FIG. 20,they permit the shoulder slide 25 to be projected therethrough intoparison forming position, and after the bottle has been formed from theparison the separation of the slides 118 and 119 permits the ejection ofthe bottle 115 from the body die 20. The body die 20 may be substitutedfor the body die 20 in either the mechanism shown in FIG. 3 or themechanism shown in FIG. 15, according to which the parisons and bottleswill be produced in the manner explained in connection with thesefigures.

FIGS. 17 to 19 inclusive show another form of mechanism by which thebottle 115 shown in FIG. 23, may be produced. In this form of mechanismthe body die is made in two similar halves which are transverselymovable into and out of engagement with each other during operation butwhich are constrained against longitudinal movement; and the shoulderslide is also made in two similar halves which during operation aretransversely movable into and out of engagement with each other inunison with the movement of body die sections, and which are alsolongitudinally movable both in separated and contacting positions.

In referring to FIG. 17 the left-hand side thereof will again bereferred to as the forward end of the mechanism and the right-hand sidethereof as the rear end of the mechanism. As shown in FIG. 17 the bodydie 20 is made in two separate opposed halves 125 and 126 which aremovable into and out of engagement with each other. Each of the halvesis provided with a semi-circular cavity 127 which when the two halvesare in engagement with each other conform to the shape of the bottle tobe formed. One half, 125, is secured in fixed position to a slide 128which is slidably mounted upon a pair of longitudinally spacedtransversely extending rods 12-9, and the other half, 126, is secured infixed position to a slide 130, similar to the slide 128, which is alsoslidably mounted upon the rods 129. The rods 129 are secured to andbetween a pair of similar platens 131 and 132 which are mounted in fixedposition upon the rods 14. The slides 128 and 130 are adapted to bemoved toward and away from each other upon the rods 129, to open 12 andclose the body die halves and 126, by pistons, not shown, which areslidably mounted in cylinders 133, carried by the platens 131 and 132,and connected to the slides 128 and 130 by piston rods 134.

The cover die 33 is secured to a platen 135, which is slidably mountedupon the rods 14 forwardly of the body die 20 for back and forthmovement toward and away from the body die 20 by cylinders 136 which arecarried by the platen and are slidably mounted upon fixed pistons 137which are connected to the platen 135 by piston rods 138.

The shoulder slide 25- is made up of two similar op posed halves 140 and141 which are slidably mounted, by gibs 142, upon a platen 143 fortransverse movement into and out of engagement with each other. Theblowtube 29 is also carried by the platen 143 which is slidably mountedupon the rods 14. The platen 143 and the blow-tube 29 are adapted to bemoved back and forth to bring the shoulder slide 25 and the blow-tube 29into operative relationship with the cover and body dies by the samemechanism as shown and described in connection with FIG. 15 and the samereference characters are applied to like parts in both FIGS. 15 and 17.

The body die half 125 is provided with a small longitudinally extendingcylindrical bore 145, and the body die half 126 is provided with asimilar bore 146. The shoulder slide half 140 is provided with anelongated forwardly extending pin 147, and the shoulder slide half 141is provided with a similar pin 148. When the body die 20 and shoulderslide 25 are in separated open position the pins 147 and 148 carried bythe shoulder slide, are in axial alignment with the bores 145 and 146,respectively, in the body die. With the body die 20 and shoulder slide25 in open separated position, when the shoulder slide is movedforwardly the pins 147 and 148 will enter the bores 145 and 146, andthen when the body die is opened and closed, by the actuating meanstherefor, the shoulder slide will be opened and closed in unisontherewith. FIGS. 18 and 19 show the body die 20 and shoulder slide 25 inclosed bottle forming position. Otherwise the construction of themechanism shown in FIG. 17 is the same as that shown in FIGS. 3 and 15and like numerals as applied to like parts.

In operation after the shoulder slide 25, in open condition, has beenprojected forwardly into proper position in the body die, the body dieand shoulder slide are moved to the closed position as shown in dottedlines in FIG. 17, after which, or simultaneously therewith the blow-tubeis moved up to parison forming position, also shown in dotted lines. Thecover die is then moved up into operative engagement with the shoulderslide. After the parison has been formed, the shoulder slide isretracted to bottle forming position after which the parison is expandedinto shape. After the bottle has cooled and set, the body die andshoulder slide are opened leaving the bottle on the blow-tube from whichit is then removed.

FIG. 24 shows a modified form of bottom slide means, generally indicatedby numeral 150, which may be substituted for the bottom slide means41-42 in FIGS. 3, l5 and 17 for producing a bottle 151, shown in FIG.25, to have an indented bottom as indicated at 152. As shown in FIG. 24the bottom slide means 150 comprises two opposed slides 153 and 154which are slidably mounted on the open end of the body die 20 in thesame manner as the slides 41 and 42 are mounted thereon by the gibs 43.The slide 153 may be actuated by the cylinder and piston construction 44to 47 shown in FIG. 3, and the slide 154 may be actuated by the cylinderand piston construction 48 to 51, also shown in FIG. 3. The slide 154 atthe inner end thereof is provided with a recess 155 in which a contourblock 156 is slidably mounted for movement toward and away from the bodydie 20. The rear or inner face 157 of the contour block 156 has the samecontour as the indentation, in the bottle 151, to be formed by thebottom slide means 150. The

, 13 block 156 is provided with a plurality of longitudinally extendingguide rods 158 which extend out through recess 155 and apertures 160 inthe slide 159, and are provided with adjusting nuts 161. Coiled springs162, which are disposed about the rods 158 between the nuts 161 and theouter face of the slide 154 yieldingly bias the the block 156 into therecess 155 until the surface 157 thereof coincides with or drops belowthe forward face of the body die 21 The slide 153 carries a plunger 163having a wedge-shaped end 164 and a pair of antifn'ction rollers 165mounted therein. As the slide 153 is moved into engagement with theslide 154 the wedgeshaped end 164 of the plunger 163 enters the recess155 behind the retracted contour block 156 and upon further movementthereof forces the block 156 by cam action out from the recess 155 tothe position shown in FIG. 24. After the blown bottle has cooled to setcondition, the slide 153 is first retracted to open position whichpermits the springs 162 to withdraw the block 156 back into the recess155, after which the slide 154 and with it the block 156 are retractedto open slide position.

In producing bottles having exteriorly threaded necks, as heretoforedescribed herein, the inner wall of the neck is forced away from theblow-tube and is slightly indented opposite the exterior neck threadsduring the blowing of the parison into bottle shape, as shown at 171 inFIGS. 6 and 12. Also in some instances, the neck forming portion of theparison, usually due to the type of molding materials used, is notforced into the neck and thread forming section of the shoulder slidewith sufficient force to produce perfect exterior neck threads. This isnot always critical, but where it is critical, means are provided bywhich a smooth inner neck wall and heavily compacted threads areproduced.

This may be accomplished in several ways, one of which, as shown in FIG.14, is to constructthe blowtube in such a manner that after the bottlehas been blown into shape, the inner wall of the neck may be ironed intosmooth condition, and simultaneously therewith the neck material firmlycompacted into the neck forming section of the shoulder slide. Anotherway of accomplishing this is to construct the shoulder slide andblow-tube, as shown in FIGS. 26 and 27, in such a manner that themolding material is forced under pressure into a neck forming section ofthe blow-tube during the injection of the molding material in formingthe parison. FIG. 28 shows another construction of the shoulder slideand blow-tube by which the neck of the bottle may be formed during theforming of the parison. FIG. 13 shows the blowtube made in such a mannerthat the neck of the bottle may be firmly compacted within the neckforming section of the shoulder slide, and at the same time femalethreads are formed in the inner wall of the neck.

Referring first to FIG. 14, the blow-tube 29 is shown as made up of thecylindrical body section 171 which is slidably mounted in the bore 26 ofthe shoulder slide 25 and is provided with a central longitudinal bore172 throughout the length thereof. A cylindrical rod 173 is slidablymounted in the bore 172 and extends out through both ends thereof. Theforward end of the rod 173 beyond the bore 172 is provided with anenlarged cylindrical extension 174 which is of slightly greater diameterthan the diameter of the bore 172 and rod 173, thereby defining anannular shoulder 175 between the rod 172 and extension 174. In operationthe extension 174 is disposed in the position shown in dotted lines inFIG. 14 with respect to the shouldered end 176 of the section 171 of theblow-tube, whereby the distance between the shouldered end 176 of thesection 171 and the shoulder 175 between the rod 173 and the extension174, is approximately equal to the length of the bottle neck. Theblowtube is then moved to parison forming position within the shoulderslide, after which the molding material is injected into the bore 26 inthe manner previously described to form the parison within the bore 26,about the 14 extension 174 and that part of the rod 173 which extendsbetween the shoulders and 176. The shoulder slide is then moved tobottle forming position within the body die after which the parison isexpanded to' bottle form with the inner neck wall moved slightly out ofcontact with the section of the rod 173 between the shoulders 175 and176 and slightly indented as shown at 171 in FIGS. 6 and 12. Immediatelyafter the blowing of the parison to body form and while the moldingmaterial is still in deformable condition, the rod 173 is withdrawn inthe bore 172 until the shoulder 175 is in close proximity to theshoulder 176 thereby ironing out the inner wall of the neck into smoothcondition and producing a thin narrow inwardly extending annular lip(not shown) about the mouth of the bottle. After the bottle has cooledto set condition, it may be removed from the mechanism as previouslydescribed.

Reference will now be had to FIGS. 26 and 27 of the drawings in whichthe blow-tube 29 is constructed in such a manner that the entire neck ofthe bottle is for-med by the blow-tube, instead of the shoulder slide,during the forming of the parison. As shown therein the blowtube is madein two concentric inner and outer cylindrical sections 180 and 181. Theouter section 180 is slidably mounted in the bore 26 of the shoulderslide 25, and the inner section is slidably mounted in a complementarybore 182 in the outer section 180. The forward end of the outer section180 of the blow-tube is provided with a rearwardly extending annularrecess 183, about the inner section 181, of the same length and diameteras the bottle neck, the inner wall of which is provided with a femalethread 184 complementary to the exterior male threads on the bottleneck. Then with the blow-tube disposed in parison forming position, asshown in FIG. 26, and the inner section 181 disposed in the positionshown in FIG. 27 with respect to the outer section 180, when the moldingmaterial is injected under pressure, as previously described to form theparison within the shoulder slide bore 26 about the outer end of theinner section 181, the neck of the bottle is formed within the recess183 about the inner section 181 and is firmly compacted therebyproviding a smooth inner neck wall and welldefined threads thereabout.After the bottle has cooled to set condition the shoulder slide,blow-tube and finished bottle carried thereby are projected out of thebody die, as shown in FIG. 27, after which the bottle may be removed aspreviously described. It should be noted that when the construction ofthe blow-tube, as shown in FIGS. 26 and 27, is used, the wall of thebody forming section of the parison is considerably thicker than thatpreviously shown, which is acceptable for producing some types ofbottles.

In FIG. 28 is shown a modified type of body die, shoulder slide, andblow-tube by which the neck of the bottle may be formed during theforming of a thin-walled parison such as shown in FIGS. 3 to 7. Thistype of mechanism necessitates the use of a split body die and shoulderslide and the use of the mechanism shown in FIG. 17, or one similarthereto. As shown in FIG. 28 the blowtube comprises an outer cylindricalsection which is slidably mounted in the shoulder slide bore, and aninner elongated cylindrical section 191 which is slidably mounted in anaxial bore 192 in the outer section 190. The forward end of the outersection 190 is provided with an enlarged cylindrical head 193 having arearwardly extending recess 194 therein, about the inner section 191, ofthe same length and diameter as the bottle neck, the inner wall of whichis provided with a female thread 195 complementary to the male threadabout the bottle neck. Adjacent the rear end thereof the shoulder slidehas a cavity 196, complementary to the head 193, in which the 7

